invoices_email_defaults

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so description carries the burden. It discloses what the tool returns (suggested to/cc/subject/body with substituted variables) which implies it reads template data rather than mutating. It does not disclose whether this counts against rate limits, whether company template config may be required, or edge behaviors. For a read-only suggestion tool this is reasonably transparent but not rich.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, front-loaded with the core purpose first, then the returned fields, then guidance. Zero waste, no redundant phrasing. Excellent structure.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

This is a straightforward read-only pre-fill tool with 1 required param (uuid). No output schema, but the returned fields are enumerated in the description (to, cc, subject, body). For its simplicity, the description covers the essential behavior. Sibling invoices_email exists and the chain is clear. Could mention that delivery_notes_email_defaults and receipts_email_defaults share the same pattern, but that's not essential.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the baseline is 3. The description adds context about template-variable substitution but doesn't elaborate on parameter semantics beyond that. The language param enum (ro/en) and companyId override are documented in schema. Description adds marginal value: it clarifies output fields but not parameter usage details.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Description has a specific verb+resource: 'Get pre-filled email content for an invoice based on the company email template'. It clearly states what is returned (to, cc, subject, body with template variables substituted) and differentiates from the sibling invoices_email (which actually sends).

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

States clear usage: 'Use this to populate the email form before calling invoices_email.' This gives a when-to-use and a clear chain (populate form, then send). It doesn't explicitly state when NOT to use it or name alternatives, but the purpose is distinct enough from siblings (email_defaults vs email) that guidance is adequate.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.